Fix conflicting nullability specifier warnings

[kiyot]

Compiler generates warnings when using OIDExternalUserAgentIOS. This PR fixes those warnings.

The warnings are the same as the ones in #60, and what this PR does is basically the same as #79. But #79 misses OIDExternalUserAgentIOS, and this PR compensates for it.

[WilliamDenniss]

Thanks for the contribution! Can you sign the CLA (or point me at your CLA if you did that already) so I can review it?

[kiyot]

I have signed the CLA using my name(Kiyotaka Sasaya).

[kiyot]

@WilliamDenniss This is the link to the CLA.

[S2Ler]

@WilliamDenniss Please merge the PR.

[codecov-io]

Codecov Report

Merging #410 into master will increase coverage by 12.03%. The diff coverage is n/a.

@@             Coverage Diff             @@
##           master     #410       +/-   ##
===========================================
+ Coverage   72.13%   84.17%   +12.03%     
===========================================
  Files          63       52       -11     
  Lines        5412     4632      -780     
===========================================
- Hits         3904     3899        -5     
+ Misses       1508      733      -775     

Impacted Files	Coverage Δ
Source/OIDAuthState.m	46.02% <0.00%> (-1.00%)	:arrow_down:
Source/OIDAuthorizationService.m	53.43% <0.00%> (-0.38%)	:arrow_down:
Source/macOS/OIDRedirectHTTPHandler.h
Source/iOS/OIDExternalUserAgentIOSCustomBrowser.m
...e/macOS/LoopbackHTTPServer/OIDLoopbackHTTPServer.m
Source/macOS/OIDAuthState+Mac.m
Source/iOS/OIDExternalUserAgentIOSCustomBrowser.h
Source/iOS/OIDAuthState+IOS.m
Source/macOS/OIDRedirectHTTPHandler.m
Source/macOS/OIDAuthorizationService+Mac.m
... and 2 more

---

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[bpollman]

@WilliamDenniss Will this PR get merged anytime soon? 🤞

[S2Ler]

Anyone?

[pertau]

Any update on this?

[codecov-commenter]

Codecov Report

Merging #410 into master will decrease coverage by 10.98%. The diff coverage is n/a.

@@             Coverage Diff             @@
##           master     #410       +/-   ##
===========================================
- Coverage   83.75%   72.77%   -10.99%     
===========================================
  Files          50       33       -17     
  Lines        4617     2490     -2127     
===========================================
- Hits         3867     1812     -2055     
+ Misses        750      678       -72     

Impacted Files	Coverage Δ
UnitTests/OIDURLQueryComponentTestsIOS7.m
UnitTests/OIDTokenResponseTests.m
UnitTests/OIDGrantTypesTests.m
UnitTests/OIDTokenUtilitiesTests.m
UnitTests/OIDRegistrationResponseTests.m
UnitTests/OIDAuthStateTests.m
UnitTests/OIDAuthorizationRequestTests.m
UnitTests/OIDResponseTypesTests.m
UnitTests/OIDAuthorizationResponseTests.m
UnitTests/OIDEndSessionRequestTests.m
... and 7 more

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[ChrisPearce]

Is there any update of whether this PR will be merged?

Our CI build processes continue to show conflicting nullability specifier warnings when using this library

[codecov-io]

Codecov Report

Merging #410 (5ca9d62) into master (e191b1b) will increase coverage by 17.68%. The diff coverage is n/a.

:exclamation: Current head 5ca9d62 differs from pull request most recent head 44fca89. Consider uploading reports for the commit 44fca89 to get more accurate results

@@             Coverage Diff             @@
##           master     #410       +/-   ##
===========================================
+ Coverage   66.49%   84.17%   +17.68%     
===========================================
  Files          41       52       +11     
  Lines        2895     4632     +1737     
===========================================
+ Hits         1925     3899     +1974     
+ Misses        970      733      -237     

Impacted Files	Coverage Δ
Source/AppAuthCore/OIDRegistrationRequest.h
Source/AppAuthCore/OIDRegistrationRequest.m
Source/AppAuthTV/OIDTVAuthorizationResponse.m
Source/AppAuthCore/OIDRegistrationResponse.m
Source/AppAuthCore/OIDTokenRequest.h
Source/AppAuthCore/OIDServiceConfiguration.h
Source/AppAuthCore/OIDScopeUtilities.m
Source/AppAuthCore/OIDTokenResponse.m
Source/AppAuthCore/OIDDefines.h
Source/AppAuthCore/OIDAuthorizationResponse.m
... and 83 more

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